Trenching machines commonly include a digging chain supported on a boom. In use, the boom extends from the machine and downwardly, and the digging chain is fastened to and around the boom. The digging chain supports a plurality of spaced apart digging or cutting teeth which contact the ground to be trenched.
During operation of the trencher, as the chain moves continuously along the edge of the boom, the frictional contact between the chain and surfaces of the boom causes wear of the chain links, and this wear is aggravated as dirt and grit comes between the chain and the boom during trenching.
Additionally, during operation of the trencher, if the cutters encounter obstructions or hard material, backflexing of the chain links tends to occur as cutters supported by the links contact the surface being trenched. This backflexing of the chain links and cutters tends to reduce the effectiveness of the cutters and may also cause increased friction between certain surfaces of the chain and the boom of the trencher and uneven chain link wear.
While in some prior art chain link sidebars a central portion of the edge that slidingly contacts a supporting surface has been induction hardened in an effort to reduce chain wear, the prior art does not provide a sidebar with effective means to reduce chain wear at the forward and rearward ends of the edge of the chain link where frictional wear is greatest.